1. Field of the Invention
The present invention relates to an apparatus and method for preserving a region code for an optical disk drive in an internal flash memory contained in a microcomputer.
2. Description of the Related Art
Since the DVD industry split the world up in several DVD regions to prevent illegal copy and distribution of DVD disks, every DVD disk has a region code. DVD disks with a region code will be only playbacked on DVD players with the same region code.
FIG. 1 shows a block diagram of a DVD-ROM drive that supports Region Playback Control II (RPC II). The DVD-ROM drive stores its region code in an external flash memory 71 or an EEPROM.
When a DVD disk is loaded, the DVD-ROM drive compares its region code with that of the DVD disk. If they do not match, the DVD-ROM drive will not play the DVD disk. The region code of a DVD-ROM drive can be changed up to five times by users and can be initialized up to five times by sellers; hence, it can be changed up to 25 times.
The change of the region code is carried out by the ATAPI command xe2x80x9cSend Keyxe2x80x9d transferred through an interface unit 51 from an external host. On receiving the command xe2x80x9cReport Keyxe2x80x9d from the external host, the DVD-ROM drive reads the current region code and sends it to the host.
Because the region code of a DVD-ROM drive should be preserved during power-off and also be rewritable, it is commonly stored in an external flash memory 71 as shown in FIG. 1. However, the employment of the flash ROM increases the manufacturing cost of an optical disk drive and also increases the size of the printed circuit board (PCB). Instead of the flash memory, an EEPROM can be adopted to store the region code. In this case, the control of the EEPROM requires several I/O ports of the microcomputer, which also leads to design and manufacturing cost problems.
It is an object of the present invention to provide an apparatus and method for preserving a region code for an optical disk drive without an external flash memory.
The method for preserving a region code for an optical disk drive in accordance with the present invention comprises the steps of receiving a region code to be written, copying a part of the firmware for the optical disk drive stored in memory means to an external memory, and writing the received region code in the memory means separately from the firmware by the execution of the copied firmware.
The apparatus for preserving a region code for an optical disk drive in accordance with the present invention comprises an interface unit receiving a region code to be written from an external host, a first memory storing the firmware for the optical disk drive, a second memory for storing a part of the firmware, and a control unit copying a part of the firmware stored in the first memory to the second memory and storing the received region code in the first memory by separating the region code from the firmware.